The present invention relates to the field of acoustic reproduction and, more particularly, to the reproduction of sound by multiple speakers having overlapping sound fields.
The process of filling a large area with sound, is usually performed by feeding the audio material to multiple speakers placed throughout the area. This technique creates certain problems, the foremost being the interference patterns that are produced when sound waves emanating from different speakers converge. Consider two speakers transmitting the same signal. At any given location relative to the two speakers, there will be certain frequencies for which constructive interference occurs, i.e., for which the sound waves reinforce each other; and there will be other frequencies for which the interference is destructive. The particular frequencies at which these different interference patterns occur are determined by the distance from each of the speakers to the location in question. The effect is also observed when loudspeakers are arranged vertically. Hence, the sound field at every point in the room will appear to be filtered by a set of frequency filters whose pass-band frequencies depend on the location relative to the speakers. In other words, listeners in different areas of the room will hear different sounds, none of which being identical to the sounds being played through the speakers.
Broadly, it is an object of the present invention to provide an improved system and method for sound reproduction.
It is another object of the present invention to provide a sound reproduction system which avoids the perception of constructive and destructive interference of sounds emanating from different loudspeakers having overlapping sound fields.
These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.